It is known in the art to which this invention pertains that during the course of manufacture metal bodies develop surface imperfections therein. Illustratively, in the automotive art, bare metal sections which ultimately form the automobile body are welded together. Inherently in this procedure there results porosity in the weld joint, and ripples or deformations in the metal surfaces proximate to the zone of the welding operation.
Quality considerations dictate that such imperfections be remedied, and the use of solder has been one means employed by the prior art. The soldering technique, however, is disadvantageous from the standpoint of being time-consuming, but also, since a flux is required, there arises the problems of toxicity and later flux removal.
One expedient currently in use in substitution for solder is a silicon bronze alloy, and one material of this type of which applicants have knowledge contains approximately 2.8 to 4.0% silicon. Silicon bronze has the significant advantage over solder of substantial time savings, since it can be applied to the metal surfaces by thermal spraying. When arc spraying is employed, there is less heat transfer to the base, and consequently less bare automobile parts of steel sheet, wherein the general sequence of steps is welding, grinding, thermal spraying, and grinding, even the use of silicon bronze as the sprayable material gives rise to disadvantageous results. Stated briefly, in the second grinding step just mentioned, time and materials expended in the performance thereof have been found to be quite substantial. Additionally, upon completion of the four steps briefly noted, less than optimum results are often noted in the areas of bond strengths and surface appearance.